Some contributions to mechanical behaviors of lacustrine deposit in Bogotá, Colombia

Abstract

This paper presents the mechanical behaviors of the lacustrine deposit, a representative soil in Bogotá, Colombia. Initially, the physical characterization of the deposit is performed via laboratory tests (grain size distribution, scanning electron microscopy, Atterberg limits and water content). This characterization intends to explain the special characteristics of the mechanical behaviors of this soil. Then, various triaxial tests are carried out with controlled loading path, strain rate change, relaxation, extensile stress, and cyclic loading. The test results reveal the shape of the yield curve for Bogotá soil (in a natural state), and also show that an increasing effect of the strain rate depends on the liquid limit. This effect is also preserved with extensile stresses (which are poorly studied in soil mechanics). Finally, other effects, such as the loss of structure in the reconstituted samples and the effect of shear modulus at low strains, are studied for Bogotá soil.